Cloud Sponge, Aphrocallistes vastus (Porifera: Hexactinellida), fragment healing and reattachment

Abstract

In May 2012, fragments of Cloud Sponge, Aphrocallistes vastus, that had been cut by fishing line were deposited in an array of boulders on the seabed near the parent sponge on the southwest shore of Hutt Island in Howe Sound near Vancouver, British Columbia. Open breaks in the transplanted fragments and parent sponge healed within 12 months. The fragments reattached to rock within 24 months. Previous observers of similar events reported no healing and death of damaged sponges. However, previous observations occurred during warm El Niño periods, which may be associated with higher stress leading to unsuccessful healing. In contrast, my current observations took place in cooler La Niña conditions, which may have promoted greater resilience and better healing.